How G3 battlecruisers reshape the German surface war

What would the Royal Navy do with refitted G3 battlecruisers, and how would they fare against Gneisenau and Scharnhorst?

They would form the core of the fast fleet and could probably run down the German ships within hours, with major consequences for later Bismarck operations.

With roughly 32-knot speed, six forward-firing 16.5-inch guns, and modern fire control, the G3s could sustain a punishing stern chase that Scharnhorst and Gneisenau might not escape. Their continued service would give Britain a powerful fast pair alongside the King George V class, changing German command decisions, delaying Bismarck's sortie, and allowing Hood to enter modernization earlier. Japan would have little treaty leverage by that stage, while the United States would probably accelerate the Iowa class. If the same gun system remained available, even Vanguard's armament might change, extending the design's effects into the postwar fleet.